Underreamer.



No. 803,642. PATENTED NOV. 7, 1905.

w. J. TRAVERS.

UNDBRREAMER. APPLICATION rum; MAY 2, 1904.

ATTORNEYS.

'wear or undue strain thereon.

WVILLIAM J. TRAVERS, OF FULLERTON, CALIFORNIA.

UNDERREAMER.

Specification of Letters Patent.

Patented Nov. '7, 1905.

I Application filed May 2, 1904:. Serial No. 206.060.

To all whom it may concern.-

Be it known that 1, WILLIAM J. TRAVERS, a citizen of the United States,residing at Fullerton, in the county of Orange and State of California,have invented new and useful Improvements in Underreamers, of which thefollowing is a specification.

My invention relates to devices for reaming out or enlarging well-holesdrilled below the casing in a drilled well in order to permit the casingto be lowered farther down in the wellhole; and it is one of the objectsof my invention to secure additional strength and durability to theparts employed, to simplify the same, to impart great resistance in suchparts to the crushing strains imparted thereto while the-underreamer isin operation, to increase the facility by which an under-reamer can bepassed down through the easing into the well and by which it can beremoved therefrom, also to provide an underreamer which will be certainand reliable in its action and not liable to get out of order by reasonof excessive I accomplish these objects by means of the device describedherein and shown in the accompanying drawings, in which- Figurel is aperspective view, partly broken away, showing the cutters in theircontracted or inoperative position, which position they assume whilepassing through the well-casing. Fig. 2 is a like view showing thecutters in their expanded or operative position when below the lowerend'of the casing. Fig. 3 is a perspective view of the cutter-carryingyoke detached from the underreamer. Fig. 4 is a central longitudinalsection of my underreamer, the cutters being shown in their contractedor inoperative position in full lines and in their operative position indotted lines. Figs. 5 and 6 are back and front views, respectively, inperspective of one of the cutters. Fig. 7 is a transverse section takenon line 7 7 of Fig. 2. Fig. 8 is a transverse section taken on line 8 8of Fig. 2. Fig. 9 is a perspective view of-the yoke-supporting key.

In the drawings, A representsv the main body portion or stock of theunderreamerscrew-threaded in its upper end for engagement with theconventional screw-threaded stem of the underreamer. (Not shown.)

Through the 'centerof the stock is a central bore A, having an enlargedportion of the bore to provide housing for the spiral spring 0. At thelower end of the enlarged bore is an offset shoulder A, below which isthe contracted portion thereof. The contracted portion of the bore belowthe shoulder A is of a diameter adapted to receive the spring-supportedbolt B. This bolt is provided on its upper end with a head B, forming anabutment which rests upon the spiral spring G and is supported thereby,the said spring extending from the head of the bolt down to and restingupon the offset shoulder A in stock, and thereby holding the boltspring-pressed in its elevated position for the purpose of holding thecutters in their elevated, extended, and operative position.

Transversely mounted in the cutter-supporting boltB is theyoke-supporting key D, (shown in enlarged detail in Fig. 9,) which alsoextends through the holes E in the cuttor-supporting yoke E. Thecutter-supporting yoke has a longitudinal movement on dovetail lugs A onthe stock A, Fig. 1. Removably mounted in the lower end of thecutter-supporting yoke are the cutters F. These cutters are providedwith longitudinal flanges or lugs F, which hold these cutters in aslidable position in the yoke. The longitudinal flanges F on the cuttersare adapted to bear against and be held in place in the yoke by thelongitudinal shoulders E" therein. The inclined cutter-supportingshoulder G in the bottom thereof has an upward inclination toward itscenter and forms a bearing-surface adapted to engage the cutters F. attheir bottom ends and crowd them into their outer or operative position.The inclined shoulders A' on the lower end of the stock are adapted tocrowd the upper ends of the cutters also into their outer or operativeposition when the tension of the spring 0 contracts the space betweenthe inclined shoulders G on the bottom and the inclined shoulders A atthe top, which will spread the cutters apart into their operativeposition. This will occur whenever the cutters pass below the casing(not shown) of the well. In practice a block of wood is inserted betweenthe top of the yoke and shoulder on the stock to relieve friction ofcutters against casing when reamer is going down and is crushed out whenreamer strikes bottom. Projecting upwardly from the bottom of theyokeinto which itis screwed is the square cutter-supporting bar H. Thisbar is screw-threaded at its lower end and,

adapted to be screwed into the female thread in the lower end of theyoke. hen the bar is screwed tightly therein, the shoulder G, having asquare aperture therein to receive IIO the bar H, is permitted to dropinto place in the bottom or return bend of the yoke, as shown in Figs. 3and 4:. This bar will hold the cutters apart and in position to bespread into their extended operative position when the cutters passbelow the well-casing, crushing the block of wood on contact of the yokewith the bottom of well, at which time the spring will contract and drawthe yoke upwardly. The cutters being between the upper and lowerinclined shoulders will be crowded into their operative position, thecutters having been held by the bar H in position ready to be crowdedapart as the upper and lower inclined shoulders are drawn together andassume the operative position. (Shown in dotted lines in Fig. 4.) Thelongitudinal lugs F on the cutters will pass into and be held in thegrooves I, Fig. 4, the said grooves being formed by bearing-surfaces onthe downwardly extension A of the main body portion of stock on one sideand the shoulder E on the other side. When in this operative position,the cutters being expanded they will be firmly held against breakage ormovement from their place therein no matter what the jars thereon orwear may be. In the lower end 01 the yoke I have provided clearanceholesJ for the passage therethrough of sand or other material that mightotherwise lodge between the cutters and prevent the proper closing ofsame.

To support the yoke carrying the cutters to the main body or stock, Ihave provided the key D, which is wide and strong, but thin incross-section. It is provided on its lower edge with an offset D,providing a shoulder D, adapted to engage when in place the body portionof the yoke immediately below the aperture E therein, which point 1smarked K in Fig. 3. The shoulder on the key will rest firmly against thesame. To further prevent the accidental removal of this key, I haveprovided an aperture (Z in the key for the passage therethrough of alocking-bolt (not shown) to hold the key in place firmly against theshoulder K. To further secure this key against movement when in place111 the yoke, I have provided a screw-threaded recess cl in the cornerof the key, and I have also placed in the lower corner of the slot E inthe carrier a corresponding screw-threaded recess adapted when the keyis in place to receive and engage the screw-threaded bolt L. (Shown inFig. 2.) The union of these screwthreaded recesses when they registerone with the other when the key is in place will form a screw-threadedsocket for the reception of the screw-threaded shank on thelocking-bolt, and when tightly screwed therein will securely hold thekey in place.

On the downwardly-projecting extension A of the stock I have mountedlongitudinal lugs 60, Fig. 1, adapted to enter the vertical recesses fon the inner face of the cutters F,

Figs. 5 and 6, the purpose of which is to prevent entrance of sand andgravel when the cutters are assuming their operative position.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is

1. An underreamer comprising a stock having a central bore therein. thesaid here being provided with a spring-engaging shoulder; ayoke-supporting bolt in said bore having a bearing-head adapted toengage the upper end of a spiral spring surrounding the same and anaperture in the lower end thereof for the reception of a key, the saidaperture adapted to register with openings on the yoke for the receptionof said key on said bolt, a spiral spring surrounding said bolt andadapted to hold the bolt in an elevated position, the said stock beingprovided with guideways for the reception and operation of acutter-supporting yoke: a cutter-supporting yoke being provided withlongitudinal recesses having dovetail grooves therein for the receptionand engagement therewith of the longitudinal lugs on the stock, the saidyoke having at the top thereof apertures for the reception of ayokesupporting key; a yoke-supporting key in said aperture and in saidbolt; cutters slidably mounted in hearings in said yoke and in saidstock.

2. In an underreamer of the character herein described a yoke therefor,longitudinal bearing-faces with dovetail recesses therein" and adaptedto receive and engage dovetail lugs on the stock and provided at itsupper end with apertures for the reception of the yoke-supporting key; astock having dovetail lugs adapted to enter recesses in the yoke; and ayoke-supporting key in said aperture.

3. In an underreamer of the character herein described having a stock Awith a central bore therein and cutter-engaging lugs 64 thereon, and acutter-carrying yoke E slidably mounted on the stock and having groovesE therein to slidably engage lugs on the stock, cutters F, havinglongitudinal grooves f therein for the reception of the lugs (6 on thestock and provided with longitudinal lugs F adapted to enter groovesprovided therefor in the yoke substantially as herein shown anddescribed.

4. In an underreamer of the character herein described a stock providedwith longitudinal depressions on both sides of the lower end, and havingon these two sides bearingfaces provided with longitudinal dovetailyoke-engaging lugs extending along said bearing-faces and having atransverse slot therethrough for the reception of a yoke-supporting key;a downwardly-projecting extension on the end of the said stock forming abearing-face for cutters; a cutter-supporting yoke having a central borefor the reception of a yoke -supporting bolt and a spiral springthereon; a yoke-supporting bolt and spiral spring therein; the said yokehaving a transverse opening therethrough for the reception of ayoke-supporting key, a yoke-supporting key therein.

5. In an underreamer of the character herein described having a stockand a cutter-supporting yoke provided with a transverse opening for asupporting-key, the lower wall of said opening being provided with aboltengaging thread adapted to register with a like thread in theyoke-supporting key; a yoke-supporting key D to removably secure theyoke to the stock, the said key being provided with a screw-threadedrecess for the reception of a locking-bolt L; a locking-bolt L in thescrew-threaded opening between the key and the yoke.

6. In an underreamer of the character herein described having acutter-supporting yoke with a return-bend at its lower end, inclinedshoulders Gr on the return-bend their inclined surfaces formingbearing-faces for the engagement with bearing-faces on the cutters andadapted to spread the lower end of the cutters apart in combination withreamingcutters substantially as herein shown and described.

7. 'In a reamer, such as herein described comprising the stock A havinga central bore; a yoke E slidably mounted therein, cutters workablysecured in said yoke. and provided with means to secure said cutters inworkable engagement with said yoke, the said yoke being provided on itsbottom return end with inclined cutter bearing shoulders adapted whenthe yoke is in its upward position to spread the cutters apart; ayoke-supporting bolt in the bore of said stock and provided withresilient means to hold saidbolt in its elevated position; and means tosecure said bolt to said yoke.

8. In an underreamer of the character herein described; a stock providedwith a central bore therein; a yoke-supporting bolt in said bore; aspiral spring surrounding said bolt the lower end resting on an ofl setshoulder in said bore, the upper end engaging a head on said bolt, thesaid stock being provided with longitudinal yoke-bearing faces andhaving clovetail lugs extending along said bearing-faces adapted toenter recesses in the yoke; a yoke adapted to pass up on either side ofthe stock and having stock bearing faces adapted to slidingly engage thesaid faces on the stock; longitudinal dovetail recesses adapted toreceive and slidingly engage the dovetail lugs on the bearing-faces ofthe stock; a yoke-supporting key extending through transverse aperturesin the upper projecting end of the yoke and through an aperture in saidbolt.

9. In an underreamer provided with a body portion or stock having acentral bore therein; a yoke slidably mounted thereon over a portion ofthe length of the stock, cutters workably mounted in the yoke andadapted to be thrown into their extended operative position when theyoke is moved upward on the stock; a spiral spring in said central borefor engagement with a yoke-carrying bolt and adapted to hold the same inan elevated position; a yoke-carrying boltin said spring workablyconnected with the yoke substantially as herein shown and described.

10. In an underreamer of the character herein described provided withcutters of the character herein-shown; means to spread the cutters apartinto their operative position when removed from the casing comprising aspringoperated bolt in the bore of the stock; a key connecting said boltwith a yoke; a stock having on its lower extension inclinedcutterbearing shoulders; a yoke workably mounted on said stock' andhaving upturned inclined shoulders.

11. In an underreamer of the character herein described the combinationof the stock A; a yoke E slidably mounted thereon; means to hold saidyoke in its elevated position on said stock, comprising ayoke-supporting bolt B, a spiral spring C surrounding said bolt andadapted to hold the same in its elevated position; a key D transverselymounted in said stock and having a longitudinal movement therein, thesaid key passing through the said bolt, theprojecting ends extendingthrough apertures E in the upper end of the yoke; cutters F looselymounted in the return-bend of said yoke and provided with longitudinallugs F to hold the same in said yoke; means to spread the cutters intotheir extended position when the yoke assumes its elevated position,comprising inclined shoulders A on the downward extension A of saidstock; an inclined bearing-shoulder Gin the return-bend of said yoke,substantially as herein shown and described.

In witness that I claim the foregoing I have hereunto subscribed my namethis 25th day of April, 1904.

WILLIAM J. TRAVERS.

Witnesses:

P. A. SGHUMAGHER, BEN FLONIOH.

